1. Field of the Invention
The present invention relates to the field of displaying technology, and in particular to a transmission/reflection dual-functional electrowetting display panel.
2. The Related Arts
Electrowetting (EW) is a phenomenon that change wettability of a liquid drop on a surface of an insulation substrate by changing voltage between the liquid drop and the substrate, so as to change the contact angle to result in deformation and displacement of the liquid drop. Generally, electrowetting is a technique applicable to a reflective display device, where a voltage is applied to a water-contained liquid to change the surface tension of the water-contained liquid. For example, when a voltage is applied to a defined space of a pixel that comprises a water-resistant insulator, an electrode, a water-contained liquid, and a non-water-contained liquid, the surface tension of the non-water-contained liquid changes thereby making the non-water-contained liquid move. When a positive voltage is applied to the liquid that contains a water-contained liquid and a non-water-contained coloring liquid and a negative voltage is applied to the insulator, the non-water-contained coloring liquid moves to one side to change an emitted light thereby resulting in modification or color.
A general electrowetting display panel comprises an upper electrode, a lower electrode, and a layer of a polar solution and a layer of a nonpolar solution interposed between the two electrodes. With no voltage applied, the nonpolar solution layer covers the entire pixel zone. After getting incident, an incident light will be absorbed by the nonpolar solution layer so as to result in an effect of blocking light or an effect of color displaying. Oppositely, to make the pixel zone in a bright state, electrical voltage is applied to the upper and lower electrodes to have the nonpolar solution layer shrink to an edge portion of the pixel zone and thus no longer block light thereby inducing an effect of light transmission and a fraction of the spectrum being not absorbed and change of color being not affected. Under this condition, the zone shows a light transmittable state. If a reflective layer is arranged under the polar solution layer, then the incident light will be reflected by the reflective layer to show a bright state. If a light source is arranged under the nonpolar solution layer, then light may transmit through the nonpolar solution layer to show a bright state.
As described above, the electrowetting display (EWD) technique take advantage of the property of an ink that has a surface tension different from that of water to work as a technique of the principle for driving a display medium, which, similar to a regular display device, is generally a transmissive device that cannot clearly show an image and has reduced contrast when the surrounding environment is in a high brightness condition.